How to Find a Prime Number Using C++ Code
Prime numbers are the natural numbers that are greater than one and they are divisible by itself and 1 only for example 7 is a prime number. Deciding about a prime number which is not very large is easy but if you are presented by a very large number to tell that weather it is a prime number or not is very difficult task. You can create small C++ software or a program which will tell you whether the number is a prime number or not. Following is the step by step guide to teach you how you can write a C++ code to decide about a prime number.
Instructions
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1
I am assuming here that you have basic know how of C++ so I will only describe the steps related to finding a prime number.
First of all make sure you have included all of the basic libraries so that code does not throw an error.
I am assuming here that you have basic know how of C++ so I will only describe the steps related to finding a prime number.First of all make sure you have included all of the basic libraries so that code does not throw an error.
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2
In order to find whether a number is prime or not we need to write a small function or method to do the calculations about the prime number. For this in you C++ code write the following method.
int diviser_search(int natural_number)
{
int calculation = 2;
while (calculation < natural_number && natural_number % calculation != 0)
{
calculation = calculation +1;
}
Return (calculation);
} -
3
The above will take a natural number as input and then it will check in the while that weather it is greater than 1 or not and it will also check the natural number’s modulus calculation that whether it is completely divisible by any number other than one or not.
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4
Now we will write the main method for our program. It will take a number as an input from user and then it will pass the number to the method we defined above.
int main () {
int a;
cout <<”Please enter a number: ” ;
cin >> a;
int check == diviser_search (a);
if(check == n)
{
cout<<”number is prime”<
}
else
{
cout<<”number is not prime”<
}
return 0;
}
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5
Just write that code in your compiler and then compile and run it. Every time you need to find about a prime number or a composite number simply use this code.
